An image forming apparatus provided with a main body housing, an image forming portion accommodated in the main body housing, a power supply, and a main body frame serving as a wall portion is well known in the art. The power supply is disposed at one side of the image forming apparatus, and includes a power supply board, electronic components mounted on the power supply board, and a shield metal plate. The main body frame vertically extends and disposed between the shield metal plate and the image forming portion. The electronic components are disposed between the shield metal plate and the main body frame, and the power supply is supported to the main body frame.
The main body frame that supports the power supply is made entirely from a flame retardant resin material, and the power supply board on which the electronic components are mounted is entirely covered and protected by the shield metal plate and the main body frame.